1. Field of the Invention
The present invention relates generally to an electronic apparatus such as a portable terminal apparatus including a rotatable displaying unit such as a liquid crystal display unit component, and more particularly, to an electronic apparatus including a movable housing unit that mounts a displaying unit and can be locked at predetermined angles.
2. Description of the Related Art
For an electronic apparatus such as a portable terminal apparatus including a rotatable displaying unit component, when the posture of the displaying unit component is adjusted by rotating the component from a vertically oriented posture to a horizontally oriented posture thereof and vice versa, the displaying unit component needs to be fixed at predetermined displaying positions. Fixing at such displaying positions needs mechanical operations.
For an electronic apparatus including such a rotation mechanism, Japanese Patent Application Laid-Open Publication No. 2005-127449 discloses a two-shaft-hinge rotation mechanism and a portable telephone including the rotation mechanism and that sliding friction torque and clicking torque can be generated by exerting a load caused by a coil spring between a sliding member or a rotation shaft supporting member and a pressure-welding member (abstract, FIG. 1, etc.).
Japanese Patent Application Laid-Open Publication No. 1998-13289 discloses that, for a battery holding structure of a portable communication apparatus, a deformed leaf spring is protruded from a main body and a recessed portion into which the leaf spring enters is provided for a rotatable battery and, thereby, the leaf spring is attached or detached to the recessed portion of the battery due to rotation of the battery (abstract, FIG. 2, etc.).
Japanese Patent Application Laid-Open Publication No. 2001-156893 discloses a locking mechanism that locks rotation of a displaying unit component and a releasing mechanism therefor for an apparatus configured by fitting a rotatable displaying unit component rotatably from a vertically oriented posture to a horizontally oriented posture thereof and vice versa to a foldable main body (abstract, FIGS. 5 and 11, etc.).
However, in the case of the configuration adapted to generate sliding friction torque and clicking torque by exerting a load caused by a coil spring on a rotation mechanism using a two-shaft hinge (the above '499 publication), the stability thereof is poor because the load concentrates on the hinge and the fixation strength of a member supported by the two-shaft hinge is low or the fixation strength varies, etc. In the case of the connecting structure including the leaf spring and the recessed portion (the above '289 publication), though the structure thereof is simple, the stability thereof is insufficient. In the case of the setting mechanism that includes a thin bar to be manually operated between a vertically oriented posture (a 0-degree position) and a horizontally oriented posture (a 90-degree position) thereof and a recessed portion of the displaying unit and that holds an inserting angle, as a rotation locking setting and a releasing setting of the locking setting (the above '893 publication), the operability thereof is poor.
A structure can be used that holds a displaying unit component at a predetermined angle inside a rotating module (cam structure) connecting the displaying unit component and an arm unit. However, problems have arisen on the fixation that the holding angle for the rotating module is not constant (for example, dispersion of about ±0.7 degrees is present) and, therefore, a fitting gap is generated between a fixed unit and a displaying unit component in a closed state and an inclination of a displayed screen is generated in an opened state, etc.
The above '499 publication (abstract, FIG. 1, etc.), the above '289 publication (abstract, FIG. 2, etc.), and the above '893 publication (abstract, FIGS. 5 and 11, etc.) have no disclosure and no suggestion for the above requirements and problems and also have no disclosure and no suggestion of configurations to solve the requirements and the problems.